The present invention relates to a universal coupling adapter or transition vehicle for use with rail transportation of bi-modal rail-highway vehicles. More specifically, the invention relates to a universal coupling adapter or transition vehicle for use with transporting rail-highway vehicles by rail and constructed so that a single universal coupling adapter can be used on either end of an inter-modal rail-highway vehicle.
Modern transportation systems must be highly flexible and economically viable to meet the demands of users of those systems. For at least a century, railroad transportation has been the transportation mode of choice to ship goods from one place to another. Accordingly, many manufacturing plants were built in close proximity to rail lines. Some plants even have constructed their own railway feeder lines so that raw materials could be easily supplied to the plant by rail, and the goods manufactured thereby could be easily transported to market by rail.
In the modern business world, however, some plants and markets, especially urbanly located retail department stores, do not have their own servicing rail lines. Accordingly, an alternative mode of transportation must be used to service these entities, or at least to transport goods from a rail head to the stores. Transportation by truck is a logical alternative, using a truck to transport the goods from the rail head to the markets. This method requires that the goods be unloaded from a rail car and loaded in a truck semi-trailer. This unloading/loading activity is time consuming, and very labor intensive, thereby rendering this particular employment of trucks economically unsound.
A more enlightened approach mounts semi-trailers, loaded with goods, on rail cars themselves. Thus, when the train reaches the rail head, the entire semi-trailer is removed from the train, whereupon a tractor can be attached to the semi-trailers to transport them to the market. Some employments of this approach place the semi-trailers on a rail car having a flat bed by means of a crane, or other lifting device. This method is costly in equipment. Alternatively, a railway coupler bogie, similar in construction to a conventional railway carriage, is attached to both ends of the semi-trailers, with consecutive railway coupler bogies joined to form a train of semi-trailers.
The general construction of railway coupler bogies useful in intermodal transportation is well known in the relevant art, as is evident, for example, from the following patents.
______________________________________ Madden 2,844,108 07/22/58 Dobson 2,963,986 12/13/60 Hindin, et al. 4,342,265 08/03/82 Bakka, et al. 4,653,966 03/31/87 Wicks, et al. 4,669,391 06/02/87 Mangone 4,869,177 09/26/89 Lienard, et al. 4,922,832 05/08/90 Gourdin 4,961,676 10/09/90 ______________________________________
Generally, the railway coupler bogies of the prior art comprise a rail wheel bearing railway carriage supporting an intermodal adapter which attaches to one end of a semi-trailer. When both ends of a semi-trailer are attached to bi-modal adapters, the semi-trailer is raised, causing the road wheels of the semi-trailer to become disposed above the ground, thereby bringing the rail wheels into contact with the rails, and allowing motion of the semi-trailer and the bogies on the tracks by means of the rail wheels.
The railway bogie adapter disclosed in the patent of Ellis, U.S. Pat. No. 4,784,066, performs substantially similar to the above-described process to create a train of semi-trailers. When this adapter is used, however, a railroad worker must plan ahead which end of the train of semi-trailers will be coupled to a locomotive, or other rail car, because different embodiments of the adapter must be used depending upon which end of the train of semi-trailers will be connected to a rail car or locomotive. Thus, a user of this adapter must keep a supply of both embodiments on hand, thereby leading to cost inefficiencies. Also, the planning of the railroad worker may be unreliable considering the possibility of a late arrival who wishes to attach his semi-trailer to an already formed train.
The patent of Orb, U.S. Pat. No. 4,773,336, discloses a railroad bogie for removably supporting coupled semi-trailers. The semi-trailers used with this bogie affect the connection between successive semi-trailers themselves, in that one end of the semi-trailers bears a projecting tongue while the other end bears a corresponding, complementary slot. The thusly joined semi-trailers are attached to the bogies by means of apertured blocks or retaining pins. In order to attach a train of semi-trailers selectively at either end thereof to a locomotive, this bogie requires the use of a coupling member, distinct from the bogie, which accepts a hook on the locomotive. The required use of the coupling member contributes to the cost of use and time needed to put a train together.
The patent of Wicks, et al., U.S. Pat. No. 4,917,020, discloses a transition vehicle for connecting convertible rail-highway semi-trailers with a railway coupling mechanism usually found on a locomotive or other rail car. The transition vehicle has retractable road wheels which pivot between an extended and a retracted position. In the extended position, the road wheels engage the ground, forcing the rail wheels upward and away from the ground. When the road wheels are retracted away from the ground, the rail wheels engage the rails so that the semi-trailer can be transported by rail. This transition vehicle, due to the constant presence of the rail wheels, significantly adds to the weight associated with the semi-trailers when the road wheels are used. This added weight could limit the size of loads carried, while also possibly increasing fuel consumption, thereby increasing the cost of use.
The patent of Wicks, U.S. Pat. No. 4,981,082, discloses another type of railway-highway intermodal transportation vehicle. The use of this vehicle, however, demands that a crane be used to properly form a train of semi-trailers. The necessity of the crane can cause operations problems if space in the rail yard is limited, as well as economic problems due the cost of the crane, its maintenance, and the profits lost due to the crane's down time.